JP7063710B2 - Method for producing surface-treated silica particles and surface-treated silica particles - Google Patents

Description

The present invention relates to surface-treated silica particles and a method for producing surface-treated silica particles.

Silica particles are anti-blocking agents and slipper-imparting agents for various films such as polyester films, polyimide films, and fluororesin films; in-plane spacers for liquid crystal display elements, seal part spacers for liquid crystal display elements, spacers for EL display elements, etc. Spacer for touch panel, spacer for gap holder between various substrates such as ceramics and plastic; encapsulant for various electronic parts such as semiconductor encapsulant, sealant for liquid crystal, encapsulant for LED light emitting element; light diffusion film , Light diffusing agents used for light diffusing plates, light guide plates, antiglare films and the like; cosmetic additives such as white extender pigments; widely used in dental materials and the like.

When silica particles are used for these purposes, silica particles surface-treated with a surface treatment agent such as a silane coupling agent are known for the purpose of improving surface properties and affinity with resins.

For example, in Patent Document 2, the surface of silica obtained by oxidizing metal powder, spherical silica powder obtained by reacting metallic silicon with oxygen, spherical silica powder obtained by melting crushed silica, and the like is silane. It is described that it is treated with a coupling agent. Further, Patent Document 3 describes that the surface of the silica powder obtained by vaporizing and oxidizing the metal powder in a flame is treated with a silane coupling agent. The silicas of Patent Documents 2 and 3 do not have the same particle size distribution and show a multi-dispersion system particle size distribution. On the other hand, silica particles having a more highly controlled particle size distribution may be required. For example, Patent Document 2 describes that coarse particles are cut. However, even if the coarse particles of the multi-dispersion silica particles are cut, there is a limit in increasing the uniformity of the particle size, and the number of coarse particle cutting steps increases, which complicates the production.

On the other hand, Patent Document 1 describes that the surface of silica particles obtained by firing a hydrolysis / condensate of alkoxysilane is treated with a silane coupling agent.

Japanese Unexamined Patent Publication No. 2008-137854 Japanese Unexamined Patent Publication No. 2005-171208 Japanese Unexamined Patent Publication No. 2015-189637

Silica particles obtained from an alkoxysilane hydrolyzed / condensate as in Patent Document 1 have excellent monodispersity and excellent particle size uniformity. Therefore, even if the particles are not classified, the uniformity of the particle size is better than that of the multi-dispersion silica particles as in Patent Documents 2 and 3, and if the particles are classified, the uniformity is further improved.

However, the higher the uniformity of the particle size, the higher the viscosity when the silica particles are mixed with the resin. Such a problem does not exist in the polydisperse silica particles as in Patent Documents 2 and 3, and is peculiar to the monodisperse silica particles. In particular, when the surface of monodisperse silica particles is treated with a silane coupling agent, this increase in viscosity becomes large.
Therefore, in the present invention, the surface of silica particles having a high uniformity of particle size is treated with a silane coupling agent to suppress an increase in the viscosity of the mixture even when mixed with a resin, or a surface-treated silica particle or a surface treatment. The subject was to provide a method for producing silica particles.

The surface-treated silica particles of the present invention that have solved the above problems are surface-treated with a nitrogen-containing compound and an epoxy group-containing silane coupling agent, and the ratio of maximum particle size / average particle size is 2.0 or less. It is characterized in that the nitrogen content measured by the inert gas melting-heat conductivity method is more than 0 ppm and 500 ppm or less on a mass basis.
The surface-treated silica particles of the present invention preferably have a maximum particle diameter of less than 3.0 μm or a coarse matter amount of 20 μm or more of 0.5% or less. It is also preferable that the surface-treated silica particles of the present invention are unclassified, the surface of the calcined silica particles is treated, or are used for semiconductor encapsulation. The nitrogen-containing compound is preferably an aliphatic amine, an aromatic amine or a heterocyclic amine.

The present invention includes a resin composition containing the surface-treated silica particles and a resin, and a semiconductor encapsulant comprising the resin composition.

In another aspect of the present invention, silica particles obtained by hydrolyzing and firing a condensate of alkoxysilane are heated at a temperature of less than 150 ° C. in the presence of a nitrogen-containing compound and an epoxy group-containing silane coupling agent. A method for producing a surface-treated silica particle is included, which comprises a surface-treating step.
In the above-mentioned production method, the temperature of the surface treatment step is preferably 60 ° C. or higher, and the amount of the nitrogen-containing compound used is preferably 0.001 to 5 parts by mass with respect to 100 parts by mass of the silica particles. The maximum particle size of the surface-treated silica particles is preferably less than 3.0 μm, and it is also preferable that the surface-treated silica particles are unclassified.

According to the present invention, the surface of silica particles having a high uniformity of particle size can be treated with a silane coupling agent to suppress an increase in the viscosity of the mixture even when mixed with a resin.

The surface-treated silica particles of the present invention are surface-treated with a nitrogen-containing compound and an epoxy group-containing silane coupling agent, have a maximum particle size / average particle size ratio of 2.0 or less, and are melted with an inert gas. The nitrogen content measured by the thermal conductivity method is more than 0 ppm and 500 ppm or less on a mass basis.
When the conventional silica particles are surface-treated with an epoxy group-containing silane coupling agent, the silica particles aggregate alone when the silica particles are dried. However, in the present invention, when the silica particles are further surface-treated with a nitrogen-containing compound, the silica particles alone Aggregation can be suppressed, and even if this is mixed with a resin, an increase in the viscosity of the composition can be suppressed.
Further, since the silica particles of the present invention do not need to be classified, the uniformity of surface treatment can be ensured.

The surface-treated silica particles of the present invention are surface-treated with a nitrogen-containing compound and an epoxy group-containing silane coupling agent.
"The surface is treated with a nitrogen-containing compound and an epoxy group-containing silane coupling agent" means that "the surface of the silica particles is coated with a layer containing a nitrogen-containing compound-derived product and an epoxy group-containing silane coupling agent-derived product." It can be rephrased as "I am." In this case, the nitrogen-containing compound and the epoxy group-containing silane coupling agent interact with the silica particles so as to be in a physically attached state and / or a chemically bonded state, for example, and the nitrogen-containing compound. It may be present as a derivative or an epoxy group-containing silane coupling agent-derived substance, and may cover a part or all of the surface of the silica particles.

<Silica particles>
The term "silica" in the present invention refers to an oxygen-containing compound of silicon in which a silicon atom forms a three-dimensional network mainly through a bond with an oxygen atom. For the oxygen-containing compound of silicon, for example, the following composition formula R _n SiO _{(4-n) / 2} (in the formula, R represents an average composition formula of an organic group having a carbon atom directly bonded to a silicon atom. , N represents a numerical value of 0 to 1), and it is assumed that a compound in which an organic group is directly bonded to a part of a large number of silicon atoms constituting the network is also included.

The silicon compound that is the raw material of the silica particles may be any compound (organosilicon compound) that can be hydrolyzed and can form a hydrate by hydrolysis.

Specific examples of the silane compound include chlorosilane compounds such as tetrachlorosilane, methyltrichlorosilane, phenyltrichlorosilane, dimethyldichlorosilane, diphenyldichlorosilane, methylvinyldichlorosilane, trimethylchlorosilane, and methyldiphenylchlorosilane; Tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, trimethoxyvinylsilane, triethoxyvinylsilane, 3-glycidoxypropyltrimethoxysilane, 3-chloropropyltrimethoxysilane, 3 -Mercaptopropyltrimethoxysilane, 3- (2-aminoethylamino) propyltrimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, Alkoxysilane compounds such as 3-glycidoxypropylmethyldiethoxysilane, 3-chloropropylmethyldimethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, dimethoxydiethoxysilane, trimethylmethoxysilane, trimethylethoxysilane; tetraacetoxysilane, Examples thereof include acetoxysilane compounds such as methyltriacetoxysilane, phenyltriacetoxysilane, dimethyldiacetoxysilane, diphenyldiacetoxysilane, and trimethylacetoxysilane; and silanol compounds such as dimethylsilanediol, diphenylsilanediol, and trimethylsilanol; Among the above-exemplified silane compounds, the alkoxysilane compound is particularly preferable because it is more easily available and the obtained silica particles do not contain a halogen atom as an impurity.

By hydrolyzing and condensing a silicon compound (raw material) in an organic solvent containing water, silica particles (fine particles) that are spherical, have a narrow particle size distribution, and have the same particle size can be obtained in a suspended state. .. By passing the reaction liquid of the silica particles through a filter, it is possible to further reduce the coarse particles.

After the silica particles are taken out from the organic solvent and dried, the silica particles are calcined to decompose the silanol group [≡SiOH, = Si (OH) ₂ , −Si (OH) ₃ ] which is a hydrophilic group ( That is, by decomposing the hydroxyl group) and closing the pores, the fired silica particles have low hygroscopicity, narrow particle size distribution, uniform particle size, and contain almost no agglomerates with large particle size. Is obtained. Preferred silica particles are obtained by hydrolyzing the alkoxysilane and calcining the condensate.
The silica content in the silica particles is preferably 99.9% by weight or more.

The firing temperature is preferably in the range of 1000 to 1200 ° C, more preferably in the range of 1050 to 1100 ° C. If the firing temperature is less than 1000 ° C., silanol groups remain, so that the obtained calcined silica particles have high hygroscopicity. When the firing temperature exceeds 1200 ° C., the silica particles are fused to each other, so that agglomerates (secondary agglomerates) are generated. That is, the obtained calcined silica particles contain agglomerates. It is difficult to crush (crush) the agglomerate even by using a crusher (crusher). Although the firing time of about 1 hour is sufficient, it may be set according to the firing temperature, the particle size of the silica particles, and the like. Further, the firing may be performed in the air.

The average particle size of the silica particles (preferably calcined silica particles) before the surface treatment is preferably 0.01 to 10 μm, more preferably 0.02 to 7 μm, and more preferably 0.05 to 5 μm. Is even more preferable. When the average particle size of the silica particles is within the above range, the viscosity of the resin composition can be kept low, and it can be applied to various applications such as electronic component materials that require precision. The average particle size is expressed as an arithmetic mean value of the volume-based particle size distribution obtained by measuring with a laser diffraction / scattering type particle size distribution measuring device (LA-920 manufactured by HORIBA, Ltd.).

The specific surface area of the silica particles is preferably 30 to 1000 m ² / g, more preferably 100 to 700 m ² / g, and even more preferably 150 to 500 m ² / g. The specific surface area of the silica particles can be measured by the BET method.

The average spherical ratio of the silica particles is preferably 1.2 or less, more preferably 1.1 or less, still more preferably 1.05 or less, and preferably 1 or more.
For the average spherical ratio, the silica particles are observed with a transmission electron microscope (magnification magnification 200,000 times), the major axis and the minor axis are measured for one silica particle, and the spherical ratio (major axis / minor axis) is calculated. It can be obtained by averaging the spherical ratios measured for 50 silica particles.

As the silica particles, it is preferable to use a group of silica particles having the same average particle size and / or specific surface area from the viewpoint of uniformity of particle size.

<Nitrogen-containing compound>
The nitrogen-containing compound is preferably an amine compound, more preferably an aliphatic amine, an aromatic amine or a heterocyclic amine.
It is considered that the nitrogen-containing compound of the present invention protects the silanol groups on the surface of the silica particles and prevents the epoxy group ring opening (diolization) of the silane coupling agent which causes the aggregation of the silica particles.

The aliphatic amines include methylamine, ethylamine, propylamine, isopropylamine, butylamine, 2-pentylamine, 3-pentylamine, neopentylamine, hexylamine, octylamine, 2-ethylhexylamine, nonylamine, decylamine and pentadecyl. Aliphatic primary amines such as amines, cetylamines, laurylamines, stearylamines, cyclopropylamines, cyclobutylamines, cyclopentylamines, cyclohexylamines, 1-adamantanamines; dimethylamines, ethylmethylamines, diethylamines, methylpropylamines, methyls. Isopropylamine, ethylpropylamine, ethylisopropylamine, butylmethylamine, methylt-butylamine, dipropylamine, diisopropylamine, ethylt-butylamine, N-ethyl-1,2-dimethylpropylamine, dibutylamine, diisobutylamine, Di (t-butyl) amine, ethylhexylamine, dipentylamine, dihexylamine, di (2-ethylhexyl) amine, dioctylamine, didecylamine, dilaurylamine, disetylamine, distearylamine, methylstearylamine, ethylstearylamine, butylstearyl. Adipose secondary amines such as amines, methylcyclohexylamines, ethylcyclohexylamines, Nt-butylcyclohexylamines, dicyclohexylamines, di (2-methylcyclohexyl) amines; trimethylamines, 1,1-dimethylpropylamines, triethylamines, Examples thereof include aliphatic tertiary amines such as tripropylamine, tributylamine, dimethylethylamine, diethylmethylamine, diethylethylamine, dimethyloctylamine, 1,8-diazabicyclo [2.2.2] octane (DABCO); and the like. ..

Other aliphatic amines include N, N'-dimethyl-1,3-propanediamine, 1,3-pentanediamine, ethylenediamine, triethylenetetramine (N, N'-di (2-aminoethyl) ethylenediamine) and the like. Aliphatic polyamines; and the like.

Examples of aromatic amines include benzylamine, phenylpropylamine, phenylbutylamine, 1,1-dimethyl-2-phenylethylamine, 3,4-dimethylbenzylamine, aniline, methylaniline, ethylaniline, propylaniline, isopropylaniline, and butylaniline. , Lauryl aniline, stearyl aniline, dimethyl aniline, diethyl aniline, methyl benzylamine, 4,4'-methylene dianiline, naphthylamine, trimethylaniline, 4-methylphenetylamine and other aromatic primary amines; methylbenzylamine, ethylbenzyl Aromatic secondary amines such as amines, t-butylbenzylamine, diphenylamine, dibenzylamine; and the like.

Examples of other aromatic amines include aromatic polyamines such as N-benzyl-1,3-propanediamine, 2,4,6-trimethyl-1,3-phenylenediamine and 4-aminobenzylamine.

Examples of the heterocyclic amine include aziridine, azetidine, pyrrolidine, 2-methylpyrazine, piperazine, 2-methylpiperidine, 3-methylpiperazine, 4-methylpiperidine, 2,4-dimethylpiperazine, 3,5-dimethylpiperidine, 2, 6-dimethylpiperazine, 2,2,6,6-tetramethylpiperazine, piperazine, N-methylpiperazine, N-ethylpiperazine, N-isobutylpiperazine, N-cyclohexylpiperazine, N-cyclopentylpiperazine, N-phenylpiperazine, 1 -(2-Pyridyl) piperazine, 1- (4-pyridyl) piperazine, 1- (2-pyrimidyl) piperazine, morpholine, quinuclidine, pyrrol, 2-methylpyrrole, 2,4-dimethylpyrrole, 3,4-dimethylpyrrole , Pyrazole, 3,5-dimethylpyrazole, imidazole, pyridine, pyridazine, pyrimidine, pyrazine, 4-dimethylaminopyridine, indole, 3H-indole, 3-methylindole, 2-phenylindole; and the like.

Among them, aliphatic primary amines, aliphatic secondary amines, aliphatic tertiary amines, aromatic primary amines and heterocyclic amines are preferable, and hexylamine, diethylamine, triethylamine, benzylamine and aniline are more preferable. , Hexylamine, diethylamine, aniline are more preferred.

The amount of the nitrogen-containing compound used may be adjusted so that the nitrogen content on the surface of the silica particles after the surface treatment is within a predetermined range, and is 0.001 to 5 parts by mass with respect to 100 parts by mass of the silica particles. It is preferably 0.01 to 1 part by mass, more preferably 0.02 to 0.5 part by mass.

When the nitrogen-containing compound is a liquid, the nitrogen-containing compound may be mixed with the silica particles as it is, or the nitrogen-containing compound may be diluted with a solvent and mixed with the silica particles.
When the nitrogen-containing compound is a solid, the nitrogen-containing compound is dissolved in a solvent to form a solution, and this solution is mixed with silica particles. The solvent is not particularly limited as long as it dissolves the nitrogen-containing compound.

The solvent can be selected from water; an alcohol solvent and the like.

Examples of the alcohol solvent include methanol, ethanol, propanol, 2-propanol, butanol, 2-butanol, isobutyl alcohol, pentanol, methylbutanol, neopentyl alcohol, isopentyl alcohol, hexanol, 2-hexanol, heptanol, 2-. Monool solvents such as heptanol, octanol, 2-octanol, cyclohexanol, methylcyclohexanol; diol solvents such as ethanediol, propanediol, butanediol, pentanediol, methylpentanediol, ethylpentanediol; glycerin, hexanetriol Triol solvents such as: methoxyethanol, ethoxyethanol, methoxymethoxyethanol, isopropoxyethanol, butoxyethanol, isopentyloxyethanol, hexyloxyethanol, phenoxyethanol, benzyloxyethanol, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol. Monobutyl ether, triethylene glycol, triethylene glycol monomethyl ether, tetraethylene glycol, polyethylene glycol, methoxypropanol (propylene glycol monomethyl ether), ethoxypropanol, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, tri Examples thereof include ether alcohol solvents such as propylene glycol monomethyl ether and polypropylene glycol.
Of these, water and alcohol solvents are preferable, water and monool solvents are more preferable, and water, methanol and ethanol are even more preferable.

When a solvent is used, the amount of the solvent used is preferably 20 times or less, more preferably 15 times or less, still more preferably 10 times or less the mass of the nitrogen-containing compound. The amount of the solvent used is preferably 0.01 times or more, more preferably 1.5 times or more, still more preferably 2 times or more the mass of the nitrogen-containing compound. If the amount of the solvent used is 20 times or less of the mass of the nitrogen-containing compound, the solvent can be efficiently evaporated and removed in the subsequent heating step, which is also advantageous in terms of energy. The compound can be mixed more evenly with the silica particles.

The nitrogen-containing compound may be added to the silica particles in a batch, dividedly, or sequentially. On the other hand, the nitrogen-containing compound may be added uniformly to the silica particles by dropping or spraying.

The mixture of the silica particles and the nitrogen-containing compound may be prepared by adding the entire amount of the nitrogen-containing compound to the silica particles and then adding the nitrogen-containing compound, or the nitrogen-containing compound may be added where the silica particles are agitated.

The silica particles are preferably fired, but even if most of the silanol groups contained in the dried silica particles before firing are dehydrated and condensed, some of the silanol groups remain as they are without dehydration condensation. ing. Therefore, a silane coupling agent is allowed to act on the silanol groups to surface-treat the silica particles. The surface treatment of the silica particles is performed by mixing the silica particles and the silane coupling agent and heating them.

<Epoxy group-containing silane coupling agent>
In the present invention, the silane coupling agent is an epoxy group-containing silane coupling agent, and the epoxy group-containing silane coupling agent may be any silane coupling agent having one or more epoxy groups in the molecule.

Examples of the epoxy group-containing silane coupling agent include 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 3-glycidoxy. Examples thereof include propylmethyldiethoxysilane and 3-glycidoxypropyltriethoxysilane. Of these, 3-glycidoxypropyltrimethoxysilane is particularly preferable.

<Other silane coupling agents>
The epoxy group-containing silane coupling agent may be used in combination with other silane coupling agents.
Examples of the silane coupling agent include methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylmethoxysilane, trimethylethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, and 3-chloropropylmethyl. Dimethoxysilane, 3-chloropropyltrimethoxysilane, p-styryltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3- (2-aminoethylamino) propyltrimethoxysilane, 3- (2-Aminoethylamino) propyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N- Phenyl-3-aminopropyltrimethoxysilane, 3-isocyanuspropyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, trifluoro Propyltrimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxy Ekalkylsilane compounds such as silane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropylmethyldimethoxysilane; methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, vinyltrichlorosilane, methyl Chlorosilane compounds such as vinyldichlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, and methyldiphenylchlorosilane; a. Syroxysilane compound; Silazan compound such as hexamethyldisilazane; Sylanol compound such as dimethylsilanediol, diphenylsilanediol, trimethylsilanol; and the like. Is done.

The amount of the silane coupling agent (preferably an epoxy group-containing silane coupling agent) added is preferably 0.1 times or more, preferably 0.15 times or more, the theoretical addition amount of the silane coupling agent represented by the following formula (I). Is more preferable, and 0.2 times or more is further preferable. The amount of the silane coupling agent added is preferably 5 times or less, more preferably 4 times or less, still more preferably 3 times or less, the theoretical addition amount of the silane coupling agent represented by the following formula (I). If the amount of the silane coupling agent added is 0.1 times or more the theoretical amount of the silane coupling agent added represented by the following formula (I), the silica particles surface-treated with the silane coupling agent have an affinity for the resin. It is possible to improve the property and dispersibility, keep the viscosity of the resin composition low, and increase the strength. Further, when the addition amount of the silane coupling agent is 5 times or less the theoretical addition amount of the silane coupling agent represented by the following formula (I), the formation of coarse particles due to aggregation, fusion and fixation of silica particles is low. It can be suppressed.

For the specific surface area of calcined silica in the following formula (I), a value obtained by measuring by the BET method is used. The minimum coverage area of the silane coupling agent is the total area that can be covered by 1 g of the silane coupling agent when the molecules of the silane coupling agent are lined up in the minimum gap to cover the particle surface, and is usually commercially available silane. The value of the coupling agent is about 250 m ² / g to 550 m ² / g.

Theoretical addition amount of silane coupling agent (g) = specific surface area of calcined silica particles (m ² / g) x mass of calcined silica particles (g) / minimum covering area of silane coupling agent (m ² / g) Formula (I)
Minimum coverage area of silane coupling agent (m ² / g) = 6.02 × 10 ²³ × 13 × 10 ^-20 / Molecular weight of silane coupling agent Formula (II)

When the silane coupling agent is a liquid, the silane coupling agent may be mixed with silica particles (preferably calcined silica particles) as it is, or the silane coupling agent may be diluted with a solvent to form silica particles (preferably calcined silica particles). Particles) may be mixed. When the silane coupling agent is a solid, the silane coupling agent is dissolved in a solvent to form a solution, and the solution and silica particles (preferably calcined silica particles) are mixed. The solvent is not particularly limited as long as it dissolves the silane coupling agent. For example, the above-mentioned organic solvent can be used.

When a solvent is used, the amount of the solvent used is preferably 20 times or less, more preferably 15 times or less, still more preferably 10 times or less the mass of the silane coupling agent. The amount of the solvent used is preferably 0.01 times or more, more preferably 1.5 times or more, still more preferably 2 times or more the mass of the silane coupling agent. If the amount of the solvent used is 20 times or less with respect to the mass of the silane coupling agent, the solvent can be efficiently evaporated and removed in the subsequent heating step, which is also advantageous in terms of energy. The coupling agent can be mixed more evenly with the silica particles. The solvent may be the same as the solvent mentioned for the nitrogen-containing compound.

The nitrogen-containing compound and the silane coupling agent may be added to the silica particles first, or the nitrogen-containing compound may be added first, or these may be added at the same time.
The silane coupling agent may be added to the silica particles all at once, may be added separately, or may be added sequentially. The silane coupling agent can also be added as uniformly as possible by dropping or spraying.

The mixing of the silica particles with the nitrogen-containing compound and the silane coupling agent may be carried out after adding the entire amount of the nitrogen-containing compound and the silane coupling agent to the silica particles, or may be mixed where the silica particles are agitated. Compounds and silane coupling agents may be added. The mixing method of the silica particles and the nitrogen-containing compound and the silane coupling agent is not particularly limited.

The temperature at which the surface treatment of the mixture of the silica particles, the nitrogen-containing compound and the silane coupling agent is performed (surface treatment step temperature) is preferably 60 ° C. or higher, more preferably 80 ° C. or higher, still more preferably 85 ° C. or higher. The temperature at which the surface treatment is performed (surface treatment step temperature) is preferably less than 150 ° C, more preferably 140 ° C or lower, and even more preferably 130 ° C or lower. By setting the surface treatment temperature (surface treatment step temperature) to 60 ° C. or higher, the solvent can be sufficiently and efficiently removed by evaporation, and the reaction between the silica particles and the reaction between the nitrogen-containing compound and the silane coupling agent. Progresses sufficiently. By setting the temperature at which the surface treatment is performed (surface treatment step temperature) to less than 150 ° C., deterioration due to thermal decomposition of the silane coupling agent can be suppressed.

The time for surface-treating the mixture of the silica particles, the nitrogen-containing compound and the silane coupling agent is preferably 1 hour or longer, more preferably 5 hours or longer, and even more preferably 10 hours or longer. The time for performing the surface treatment is preferably 50 hours or less, more preferably 30 hours or less, and even more preferably 20 hours or less. By setting the surface treatment time to 1 hour or more, the reaction between the silica particles and the nitrogen-containing compound and the silane coupling agent proceeds sufficiently, and by setting the surface treatment time to 50 hours or less, the production efficiency and energy efficiency of the surface treatment can be improved. Can be high.

The surface treatment may be performed in a nitrogen atmosphere. By performing the surface treatment in a nitrogen atmosphere, it is possible to prevent ignition, explosion, etc. during the surface treatment, and the surface treatment can be performed safely.

The heating method is not particularly limited. The mixing of the silica particles with the nitrogen-containing compound and the silane coupling agent and the surface treatment of the mixture may be performed by one device or by separate devices. Further, the surface treatment may be performed after the mixing treatment, or the surface treatment may be performed at the same time while the mixing treatment is performed.

As the silica particles thus obtained, it is preferable that the surface of the calcined silica particles is treated. Conventionally, since surface-treated silica particles may be aggregated, fused, or fixed, it was necessary to loosen the silica particles into individual particles by crushing and classifying them. However, the surface of the present invention has been used. Since the treated silica particles are surface-treated with a nitrogen-containing compound and an epoxy group-containing silane coupling agent, the particles do not aggregate by themselves when dried, and do not need to be crushed and classified.
That is, the silica particles of the present invention are preferably unclassified, and are preferably surface-treated silica particles having the following maximum particle size and average particle size while remaining unclassified.
Such silica particles may be monodisperse silica particles having a predetermined particle size distribution.

The ratio of the maximum particle size (also referred to as D2) / average particle size (also referred to as D1) of the surface-treated silica particles of the present invention is 2.0 or less, preferably 1.95 or less, and more preferably 1. It is 90 or less. If the D2 / D1 ratio is more than 2.0, the silica particles may be polydispersed or agglomerated.

The maximum particle size of the surface-treated silica particles of the present invention is preferably less than 3.0 μm, more preferably 0.02 to 2.5 μm or less, and more preferably 0.04 to 2.0 μm or less. It is more preferably 0.1 to 1.5 μm or less, and particularly preferably 0.1 to 1.5 μm or less. When the maximum particle size is 3.0 μm or more, the silica particles may have a low uniformity of particle size and tend to be a polydisperse system.

The average particle size of the surface-treated silica particles of the present invention is preferably 0.01 to 2.5 μm or less, more preferably 0.01 to 2.0 μm, still more preferably 0.02 to 1.5 μm or less, and particularly preferably 0.02 to 1.5 μm or less. It is 0.05 to 1.0 μm or less. If the average particle size is more than 2.5 μm, it may not be usable in semiconductor applications.

The average particle size and the maximum particle size can be obtained by using, for example, a laser diffraction / scattering type particle size distribution measuring device (LA-920 manufactured by HORIBA, Ltd.). The arithmetic mean value of the obtained volume-based particle size distribution may be used as the average particle size, and the arithmetic maximum value may be used as the maximum particle size.

In the surface-treated silica particles of the present invention, the nitrogen content (preferably the nitrogen content of the surface-treated silica particles) measured by the inert gas melting-heat conductivity method is more than 0 ppm and 500 ppm or less on a mass basis. It is preferably 1 ppm or more and 450 ppm or less, more preferably 5 ppm or more and 400 ppm or less, and particularly preferably 10 ppm or more and 350 ppm or less.
When the nitrogen content is in the above range, it is possible to prevent the aggregation of silica particles caused by the epoxy group-containing silane coupling agent alone treatment.

The nitrogen content can be determined, for example, by JIS G 1228 (iron and steel-nitrogen quantification method, inert gas melting-thermal conductivity method), for example, using a TC-600 type oxygen / nitrogen analyzer manufactured by LECO. Can be asked.
Specifically, a sample (for example, surface-treated silica particles) is put into a graphite crucible in an inert gas (preferably helium or argon) as a carrier gas, and heated and melted by an impulse heating method to remove nitrogen in the sample. Extract as nitrogen gas. Nitrogen gas must be sent to the detector together with the carrier gas, and if CO or H ₂ is present, CO or H ₂ is converted to CO ₂ or H ₂ O by an oxidizer (including, for example, copper oxide), and CO ₂ may be removed with NaOH, H ₂ O may be removed with Mg (ClO ₄ ), and then measured with a thermal conductivity detector. The nitrogen gas may be separated by passing it through a separation column and then transported to a thermal conductivity detector, and the nitrogen content can be determined by measuring the change in thermal conductivity.

The coarse matter amount (coarse particle amount) of 20 μm or more of the surface-treated silica particles of the present invention is preferably 0.5% or less, more preferably 0.45% or less, still more preferably 0.43% or less. ..
In the measurement of the bulky substance, the slurry-like mixture obtained by ultrasonic treatment is passed through a sieve having an opening of 20 μm, and after drying, the mass of the residue that has not passed through the sieve is measured, and the mass of the residue is measured. / The value of the used particle mass × 100 may be set as the value of the coarse particles.

The present invention includes a resin composition containing surface-treated silica particles and a resin, and a semiconductor encapsulant comprising the resin composition.

The concentration of the surface-treated silica particles is preferably 3% by mass or more, more preferably 5% by mass or more, still more preferably 7% by mass or more, and preferably 70% by mass or less, more preferably 70% by mass or more, based on 100% by mass of the resin composition. Is 50% by mass or less, preferably 40% by mass or less, more preferably 30% by mass or less, still more preferably 20% by mass or less.

In the resin composition, the surface-treated silica particles are preferably one kind, that is, monodisperse-based surface-treated silica particles. As long as the effect of the present invention is exhibited, two or more types of silica particles having different average particle diameters and particle size distributions may be used. When two or more types of silica particles having different average particle diameters and particle size distributions are used, the fluidity of the resin composition may be improved and the packing density may be further increased. When two or more types of silica particles are used, the ratio of the silica particles may be appropriately adjusted according to the purpose of use. Since the surface-treated silica particles of the present invention do not aggregate even when used in a resin composition, it is possible to suppress an increase in the viscosity of the composition.

As the resin, one kind or two or more kinds can be used, for example, polyamides such as 6-nylon, 66-nylon, and 12-nylon; polyimides; polyurethanes; polyolefins such as polyethylene and polypropylene; PET, Polyesters such as PBT and PEN; Polyvinyl chlorides; Polyvinylidene chlorides; Polyvinyl acetates; Polystyrenes; (Meta) acrylic resin-based polymers; ABS resin; Fluororesin; Phenol / formarin resin; Cresol / formarin resin, etc. Phenol resin; epoxy resin; urea resin; melamine resin; amino resin such as guanamine resin; polyvinyl butyral resin; polyurethane resin; ethylene-vinyl acetate copolymer resin; ethylene- (meth) acrylic acid ester copolymer resin Soft resins such as and hard resins; and the like. Among the above, polyimides, polyurethanes, polyesters, (meth) acrylic resin-based polymers, phenol resins, amino resins, and epoxy resins are more preferable. Of these, epoxy resin is particularly preferable.

The epoxy resin means a compound having at least one epoxy group in the molecule, and the epoxy group means a compound containing an oxylan ring which is a three-membered ring ether. In particular, a polyfunctional epoxy compound having two or more epoxy groups in the molecule is preferable. Examples thereof include aromatic epoxy compounds, aliphatic epoxy compounds, alicyclic epoxy compounds, and hydrogenated epoxy compounds. Among these, alicyclic epoxy compounds and hydrogenated epoxy compounds are preferable from the viewpoint that a cured product (sealing) having excellent heat resistance and light resistance can be easily obtained.

The aromatic epoxy compound is a compound having an aromatic ring and an epoxy group in the molecule. As the aromatic epoxy compound, for example, a glycidyl compound having an aromatic ring conjugated system such as a bisphenol skeleton, a fluorene skeleton, a biphenyl skeleton, a naphthalene ring, and an anthracene ring is preferable. Specifically, bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, fluorene-based epoxy compounds, aromatic epoxy compounds having a bromo substituent and the like are preferable, and bisphenol A type epoxy compounds, bisphenol F type epoxy compounds and the like are more preferable. Is.
Further, as the aromatic epoxy compound, an aromatic glycidyl ether compound is also suitable. Examples of the aromatic glycidyl ether compound include epibis type glycidyl ether type epoxy resin, high molecular weight epibis type glycidyl ether type epoxy resin, and novolak aralkyl type glycidyl ether type epoxy resin.

As the aliphatic epoxy compound, for example, an aliphatic glycidyl ether type epoxy resin is suitable. Examples of the aliphatic glycidyl ether type epoxy resin include those obtained by a condensation reaction between a polyol compound and epihalohydrin. Examples of the polyol compound include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol (PEG600), propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, polypropylene glycol (PPG), glycerol, and di. Examples thereof include glycerol, tetraglycerol, polyglycerol, trimethylolpropane and its multimers, pentaerythritol and its multimers, mono / polysaccharides such as glucose, fructose, lactose, and maltose, and propylene glycol skeleton, alkylene skeleton, and oxyalkylene. Those having a skeleton and the like are suitable. As the aliphatic glycidyl ether type epoxy resin, an aliphatic glycidyl ether type epoxy resin having a propylene glycol skeleton, an alkylene skeleton, an oxyalkylene skeleton or the like in the central skeleton is suitable.

The alicyclic epoxy compound is a compound having an alicyclic epoxy group. Examples of the alicyclic epoxy group include an epoxycyclohexane group (epoxide cyclohexane skeleton), an epoxy group added directly to a cyclic aliphatic hydrocarbon or via a hydrocarbon, and the like. Examples of the alicyclic epoxy compound include 3,4-epoxycyclohexylmethyl-3', 4'-epoxycyclohexanecarboxylate, and epsilon-caprolactone-modified 3,4-epoxycyclohexylmethyl 3', 4'-epoxycyclohexanecarboxylate. , Epoxy compounds with epoxycyclohexane groups such as bis- (3,4-epoxycyclohexyl) adipate; 1,2-epoxy-4- (2-oxylanyl) cyclohexane of 2,2-bis (hydroxymethyl) -1-butanol Examples thereof include an additive, an epoxy resin containing a heterocycle such as triglycidyl isocyanurate, and the like. Among these, a compound having an epoxycyclohexane group is preferable. Further, a polyfunctional alicyclic epoxy compound having two or more alicyclic epoxy groups in the molecule is suitable because the curing rate can be further increased. Further, a compound having one alicyclic epoxy group in the molecule and having an unsaturated double bond group such as a vinyl group is also preferably used.

The hydrogenated epoxy compound is a compound obtained by hydrogenating (reducing) an unsaturated bond and an unsaturated bond of a compound having an epoxy group in the molecule. The hydrogenated epoxy compound is preferably a compound having a glycidyl ether group directly or indirectly bonded to a saturated aliphatic cyclic hydrocarbon skeleton, and a polyfunctional glycidyl ether compound is preferable. The hydrogenated epoxy compound is preferably a complete or partial hydrogenated product of the aromatic epoxy compound, more preferably a hydrogenated product of an aromatic glycidyl ether compound, and even more preferably an aromatic polyfunctional glycidyl. It is a hydrogenated product of an ether compound. Specifically, bisphenol A type epoxy compound, bisphenol S type epoxy compound, hydrogenated compound of bisphenol F type epoxy compound, hydrogenated bisphenol A type epoxy compound, hydrogenated bisphenol S type epoxy compound, hydrogenated bisphenol F type. Epoxy compounds and the like are preferred. More preferably, it is a hydrogenated bisphenol A type epoxy compound and a hydrogenated bisphenol F type epoxy compound.

The epoxy resin preferably contains a polyfunctional epoxy compound having a weight average molecular weight of 2000 or less (preferably a weight average molecular weight of 1000 or less). The content of the polyfunctional epoxy compound having such a predetermined weight average molecular weight is preferably 40% by mass or more, more preferably 60% by mass or more, and more preferably 80% by mass in 100% by mass of the epoxy resin. As mentioned above, it is particularly preferably 100% by mass.

The content of the resin (preferably epoxy resin) is preferably 1 part by mass or more, more preferably 10 parts by mass or more, still more preferably 50 parts by mass or more, and preferably 500 parts by mass with respect to 100 parts by mass of the silica particles. Parts or less, more preferably 300 parts by mass or less, still more preferably 150 parts by mass or less.

In order to cure the epoxy resin which is a resin component, a conventionally known curing agent for epoxy resin can be used. As the curing agent, an acid anhydride-based curing agent, a phenol-based curing agent, an amine-based curing agent, or the like can be used as the addition type curing agent. In addition, only one kind of curing agent may be used, or two or more kinds may be used in combination.

Examples of the acid anhydride-based curing agent include hydrogenated products of phthalic anhydride (including derivatives) (tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, trialkyltetrahydrophthalic anhydride, hexahydrophthalic anhydride). , Methylhexahydrophthalic anhydride, Methylendomethylenetetrahydroanhydride, etc.), Nasic acid anhydride, Methylnagic acid anhydride, Het acid anhydride, Hymic acid anhydride, 5- (2,5-dioxotetrahydro) Frill) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, trialkyltetrahydrophthalic anhydride-maleic anhydride adduct, alicyclic carboxylic acid anhydride such as chlorendic acid; dodecenyl anhydride succinic acid, Alibocarboxylic acid anhydrides such as polyazelineic acid anhydride, polysevacinic acid anhydride, polydodecanedianhydride; phthalic acid anhydride, trimellitic acid anhydride, pyromellitic acid anhydride, benzophenone tetracarboxylic acid anhydride, ethylene Examples thereof include aromatic carboxylic acid anhydrides such as glycol anhydride trimellitic acid and biphenyltetracarboxylic acid anhydride.

Examples of the phenolic curing agent include bisphenol A, tetrabrom bisphenol A, bisphenol F, bisphenol S, 4,4'-biphenylphenol, and 2,2'-methylene-bis (4-methyl-6-tert-butylphenol). ), 2,2'-Methylene-bis (4-ethyl-6-tert-butylphenol), 4,4'-butylylene-bis (3-methyl-6-tert-butylphenol), 1,1,3-tris ( 2-Methyl-4-hydroxy-5-tert-butylphenol), trishydroxyphenylmethane, pyrogallol, phenols having a diisopropyridene skeleton; phenols having a fluorene skeleton such as 1,1-di-4-hydroxyphenylfluorene. Novolak resin made from various phenols such as polyphenol compounds such as phenolized polybutadiene, phenols, cresols, ethylphenols, butylphenols, octylphenols, bisphenol A, brominated bisphenol A, bisphenol F, bisphenol S, and naphthols. Examples thereof include various novolak resins such as a xylylene skeleton-containing phenol novolak resin, a dicyclopentadiene skeleton-containing phenol novolak resin, and a fluorene skeleton-containing phenol novolak resin.

Examples of the amine-based curing agent include an aliphatic polyamine-based curing agent and an aromatic polyamine-based curing agent. Examples of the aliphatic polyamine-based curing agent include chain aliphatic polyamines such as diethylenetriamine, triethylenetriamine, tetraethylenepentamine, diprepyrenidamine, and diethylaminopropylamine; and cyclic compounds such as N-aminoethylpiperazine, mensendiamine, and isophoronediamine. Aliper polyamines; Examples thereof include aliphatic polyamines having an aromatic ring such as m-xylene diamine, xylylene diamine, and xylylene diamine trimer. Examples of the aromatic polyamine-based curing agent include meta-phenylenediamine, diaminodiphenylmethane, and diaminodiphenyl sulfone. Further, as the amine-based curing agent, various modified amines obtained by modifying the above-mentioned amine-based curing agent for the purpose of adjusting pot life, curing speed, compatibility with resin, and the like can also be used.

In particular, in order to keep the viscosity low in the resin composition of the present invention and secure excellent fluidity, it is preferable to use an acid anhydride-based curing agent as the curing agent, and among them, the alicyclic carboxylic acid anhydride is used. Preferably, a hydrogenated product of phthalic anhydride (including a derivative) is preferable. Further, in order to enhance the adhesiveness of the cured product to the substrate, copper wiring and electrodes, an amine-based curing agent is preferable. Further, among the amine-based curing agents, aliphatic polyamines are preferable, and chain aliphatic polyamines and cyclic aliphatic polyamines are preferable, and cyclic aliphatic polyamines are more preferable, from the viewpoint of excellent fluidity as an underfill material.

The mixing ratio of the epoxy resin and the addition type curing agent is preferably 0.5 to 1.6 equivalents of the addition type curing agent with respect to one chemical equivalent of the epoxy resin. The addition-type curing agent is more preferably 0.7 to 1.4 equivalents, still more preferably 0.9 to 1.2 equivalents, relative to 1 chemical equivalent of the epoxy resin.

In the resin composition, a conventionally known curing accelerator may be used in combination with the curing agent. Examples of the curing accelerator include an acid salt of an organic base, an aromatic compound having a tertiary nitrogen, and the like. Examples of the acid salt of the organic base include an organic onium salt such as an organic phosphonium salt and an organic ammonium salt, and an acid salt of an organic base having a tertiary nitrogen. Examples of the organic phosphonium salt include phosphonium bromide having four phenyl rings such as tetraphenylphosphonium bromide and triphenylphosphine / toluene bromide, and examples of the organic ammonium salt include tetraoctylammonium bromide and tetra. Examples thereof include tetra (C1 to C8) alkylammonium bromides such as butylammonium bromide and tetraethylammonium bromide, and examples of the acid salt of the organic base having tertiary nitrogen include organic alicyclic bases having tertiary nitrogen in the ring. Examples thereof include acid salts and organic acid salts of various imidazoles. As the curing accelerator, only one kind may be used, or two or more kinds may be used in combination.
The amount of the curing accelerator used is preferably 0.01% by mass or more and 5% by mass or less, more preferably 0.03% by mass or more, based on 100% by mass of the total amount of the epoxy resin and the curing agent. It is 3% by mass or less.

In addition, in the resin composition, instead of the above-mentioned addition type curing agent, a cationic curing catalyst such as a conventionally known thermal cationic curing catalyst or a photocationic curing catalyst can be contained. The content of the cationic curing catalyst is preferably 0.01 to 10% by mass with respect to 100% by mass of the total amount of the epoxy resin.

In addition to the resin, a polymerizable monomer may be used in the resin composition. As the polymerizable monomer, one kind or two or more kinds can be used, and examples thereof include a monofunctional monomer and a crosslinkable monomer.
The monofunctional monomer may be any compound having one polymerizable carbon-carbon double bond, and one kind or two or more kinds can be used, and (meth) acrylic acid ester; styrene, p-. Styrene-based monomers such as tert-butylstyrene, α-methylstyrene, m-methylstyrene, p-methylstyrene, p-chlorostyrene, p-chloromethylstyrene; carboxy group-containing monomer such as (meth) acrylic acid Body: Examples thereof include hydroxyl group-containing monomers such as 2-hydroxyethyl (meth) acrylate, 3-hydroxy-2-hydroxypropyl (meth) acrylate, and 3-phenoxy-2-hydroxypropyl (meth) acrylate. Specific examples of the above (meth) acrylic acid ester include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, and isobutyl (meth). (Meta) acrylic acid alkyl esters such as acrylates, tert-butyl (meth) acrylates, 2-ethylhexyl (meth) acrylates, lauryl (meth) acrylates; (meth) acrylic acid cycloalkyl esters such as cyclohexyl (meth) acrylates; 2 , 4-Dibromo-6-sec-butylphenyl (meth) acrylate, 2,4-dibromo-6-isopropylphenyl (meth) acrylate, phenyl (meth) acrylate, 2,4,6-tribromophenyl (meth) acrylate , (Meta) acrylic acid aryl ester such as pentabromophenyl (meth) acrylate; (meth) acrylic acid aralkyl ester such as benzyl (meth) acrylate and pentabromobenzyl (meth) acrylate; phenoxyethyl (meth) acrylate, phenoxy- 2-Methylethyl (meth) acrylate, 2,4,6-tribromophenoxyethyl (meth) acrylate, 2,4-dibromophenoxyethyl (meth) acrylate, 2-bromophenoxyethyl (meth) acrylate, 1-naphthyloxy (Meta) acrylic acid ester having aryloxy units such as ethyl (meth) acrylate, 2-naphthyloxyethyl (meth) acrylate, phenoxy-2-methylethyl (meth) acrylate, phenoxyethoxyethyl (meth) acrylate; phenylthio (Meta) acrylic acid ester having an arylthiooxy group such as ethyl (meth) acrylate, 1-naphthylthioethyl (meth) acrylate, 2-naphthylthioethyl (meth) acrylate; methoxypolyethylene glycol (meth) acrylate, phenoxypolyethylene Alkylene glycol mono (meth) acrylates such as glycol (meth) acrylates; (meth) acrylic acid esters having a glycidyl group such as glycidyl (meth) acrylates can be mentioned.

The crosslinkable monomer may be a compound containing a plurality of carbon-carbon double bonds. As the crosslinkable monomer, one type or two or more types can be used, for example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polyethylene glycol di (). Meta) acrylate, 1,6-hexanediol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, tetramethylene glycol di (meth) acrylate And other alkylene glycol poly (meth) acrylates; neopentyl glycol di (meth) acrylates, dineopentyl glycol di (meth) acrylates and the like neopentyl glycol poly (meth) acrylates; trimethylolpropane tri (meth) acrylates, ethoxylated. (3) Trimethylolpropane tri (meth) acrylate, propoxylation (3) Trimethylolpropane tri (meth) acrylate, epoxidation (3) Trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, etc. Trimethylolpropane poly (meth) acrylate; glycerylpoly (meth) acrylate such as glyceryltri (meth) acrylate, ethoxylated glyceryltri (meth) acrylate; pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, ethoxy. Polyfunctional (meth) acrylates such as pentaerythritol tetra (meth) acrylates, propoxylated pentaerythritol tri (meth) acrylates, dipentaerythritol penta (meth) acrylates, and dipentaerythritol hexa (meth) acrylates. Meta) Acrylate; Polyfunctional styrene-based monomer such as divinylbenzene; Polyfunctional allyl ester-based monomer such as diallylphthalate, diallylisophthalate, trimethylolpropane, trimethylolpropane; 2- (2-vinyloxy) Ethoxy) ethyl (meth) acrylate; urethane acrylate oligomer (for example, Shikou (registered trademark) series (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), CN series (manufactured by Sartmer), Unidic (registered trademark) series (DIC Co., Ltd.) ), KAYARAD (registered trademark) UX series (manufactured by Nippon Kayaku Co., Ltd.) Etc.); etc.

The content of the polymerizable monomer is preferably 1 part by mass or more, more preferably 10 parts by mass or more, still more preferably 50 parts by mass or more, and preferably 500 parts by mass or less with respect to 100 parts by mass of the silica particles. , More preferably 300 parts by mass or less, still more preferably 150 parts by mass or less.

When the resin composition of the present invention contains a polymerizable monomer, the resin composition may further contain a polymerization initiator. Examples of the polymerization initiator include a photopolymerization initiator and a thermal polymerization initiator, which may be used alone or in combination. Since some photopolymerization initiators act as thermal polymerization initiators and some thermal polymerization initiators act as photopolymerization initiators, those having both properties are irradiated with light or heated. Therefore, the active energy ray-curable aqueous resin composition can be cured. Among the polymerization initiators, the photopolymerization initiator is preferable because it does not give a thermal history to the formed film, the substrate to which the active energy ray-curable aqueous resin composition is applied, and the like.

Examples of the thermal polymerization initiator include 2,2'-azobis- (2-methylbutyronitrile), 2,2'-azobisisobutyronitrile, and 2,2'-azobis- (2,4'-. Oil-soluble initiators such as dimethylvaleronitrile), benzoyl peroxide, 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane, tert-butylperoxy-2-ethylhexanoate, etc. Persulfates such as potassium persulfate, ammonium persulfate, sodium persulfate; water-soluble peroxides such as hydrogen peroxide, water-soluble azo compounds such as 2,2'-azobis (2-amidinopropane) dihydrochloride, etc. However, the present invention is not limited to such an example. These thermal polymerization initiators may be used alone or in combination of two or more.

Examples of the photopolymerization initiator include benzophenone, 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propane-1-one, and oxyphenyl-acetylacid 2- [. 2-Oxo-2-phenylacetoxyethoxy] -ethyl ester, oxyphenylacetic acid 2- [2-hydroxyethoxy] -ethyl ester, 1-hydroxycyclohexylphenylketone, 2,4,6-trimethylbenzoyl-diphenyl-phos Finoxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphinoxide, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- (4-isopropylphenyl) 2-hydroxy-2 -Methylpropane-1-one, 2-methyl-1- [4- (methylthio) phenyl] 2-morpholinopropane-1-one, 2-morpholinopropane-1-one, iodonium, sulfonium salt, diazonium salt, (4) -Methylphenyl [4- (2-methylpropyl) phenyl])-Hexafluorophosphate, diethylthioxanthone, isopropylthioxanthone and the like, but the present invention is not limited to such examples. These photopolymerization initiators may be used alone or in combination of two or more.

The amount of the polymerization initiator is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, still more preferably 2 parts by mass or more, and preferably 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer. Parts or less, more preferably 10 parts by mass or less.

The resin composition may contain a solvent, if necessary. Examples of the solvent contained in the resin composition include the same solvents as those mentioned above.
The content of the solvent is preferably 0 parts by mass or more, more preferably 30 parts by mass or more, still more preferably 50 parts by mass or more, and preferably 2000 parts by mass or less, more preferably 2000 parts by mass or more, based on 100 parts by mass of the silica particles. It is 1000 parts by mass or less.

In addition to the surface-treated silica particles of the present invention and the above-mentioned resin components, antioxidants, reactive diluents, saturated compounds having no unsaturated bond, pigments, dyes, antioxidants, ultraviolet absorbers, and photostabilization Agents, plasticizers, non-reactive compounds, chain transfer agents, thermal polymerization initiators, anaerobic polymerization initiators, polymerization inhibitors, adhesion improvers such as inorganic fillers and organic fillers, coupling agents, heat stabilizers, antistatic agents. Bacteria / antifungal agents, flame retardants, matting agents, defoaming agents, leveling agents, wetting / dispersants, antisettling agents, thickeners / sagging inhibitors, color-coding inhibitors, emulsifiers, slip / scratch inhibitors, It may contain an anti-skin agent, a desiccant, an antifouling agent, an antistatic agent, a conductive agent (electrostatic aid) and the like.

The viscosity of the resin composition at 25 ° C. is preferably 80 Pa · s or less, more preferably 70 Pa · s or less, still more preferably 60 Pa · s or less. The lower limit of the viscosity is, for example, 0.1 Pa · s, and may be 0.5 Pa · s or 1.1 Pa · s. When the surface-treated silica particles of the present invention are used for the resin, it is possible to suppress an increase in the viscosity of the resin composition.

The viscosity of the resin composition can be measured, for example, using a Brookfield type rotary viscometer (BROOKFIELD RST-CPS Rheometer manufactured by Eiko Seiki Co., Ltd.) at 25 ° C. under the condition of a shear rate of 40 (1 / s).

In another aspect of the present invention, silica particles obtained by hydrolyzing and firing a condensate of alkoxysilane are heated at a temperature of less than 150 ° C. in the presence of a nitrogen-containing compound and an epoxy group-containing silane coupling agent. A method for producing a surface-treated silica particle is included, which comprises a surface-treating step.

In the production method, the temperature of the surface treatment step is preferably 60 ° C. or higher, and the amount of the nitrogen-containing compound used is preferably 0.001 to 5 parts by mass with respect to 100 parts by mass of the silica particles. .. The maximum particle size of the surface-treated silica particles is preferably less than 3.0 μm, and the surface-treated silica particles are preferably unclassified. The preferred range of these requirements is as described above.

The surface-treated silica particles of the present invention and the resin composition containing the same can be suitably used for semiconductor encapsulation.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited by the following examples as well as the present invention, and appropriate modifications are made to the extent that it can meet the purposes of the preceding and the following. Of course, it is possible to carry out, and all of them are included in the technical scope of the present invention.

[Analysis method of particle size / standard deviation]
Silica particles were added to methanol at a concentration of 1% by mass, and the silica particles were dispersed over 10 minutes with an ultrasonic disperser to prepare a sample for measurement. This sample was measured using a laser diffraction / scattering type particle size distribution measuring device (LA-920 manufactured by HORIBA, Ltd.). The arithmetic mean value of the obtained volume-based particle size distribution was used as the average particle size, and the arithmetic maximum value was used as the maximum particle size.

[Analysis method for coarse particles]
A mixture of 90 g of methanol and 10 g of silica particles was made into a slurry by ultrasonic dispersion for 1 hour. The obtained slurry-like mixture was passed through a sieve having an opening of 20 μm, dried, and then the mass of the residue that did not pass through the sieve was measured. The value was set to.

[Analysis method of nitrogen content]
The nitrogen content was determined by JIS G 1228 (iron and steel-nitrogen quantification method, inert gas melting-thermal conductivity method).
More specifically, a quantitative analysis of N components of each sample was performed by a thermoconductivity method using helium gas as an inert gas using a TC-600 type oxygen / nitrogen analyzer manufactured by LECO.

[Analysis method of resin viscosity]
A mixture of 22.5 g of bisphenol F type epoxy resin jER806 manufactured by Mitsubishi Chemical Co., Ltd. mixed with 27.5 g of silica particles is kneaded for 5 minutes using a rotating and revolving mixer (Awatori Rentaro AR-100 manufactured by Shinky Co., Ltd.). Defoaming was performed for 1 minute, and this was repeated 3 times to obtain a resin composition. The resin composition left to stand for 3 days was subjected to a viscosity (Pa · s) at 25 ° C. at a shear rate of 40 (1 / s) using a Brookfield type rotary viscometer (BROOKFIELD RST-CPS Rheometer manufactured by Eiko Seiki Co., Ltd.). It was measured.

Example 1
5 kg of calcined silica particles KE-S30 manufactured by Nippon Shokubai Co., Ltd. were charged into a Henschel mixer (FM20J type manufactured by Mitsui Mining Co., Ltd.) having a capacity of 20 L equipped with a heating jacket.
The Henschel mixer has a container for the mixture to be mixed and a rotating shaft with a stirring blade at the bottom of the container, and a plate-shaped blade installed along the wall surface as a device for scraping off wall deposits. A rotating shaft with a mark is installed on the upper surface of the container. A solution prepared by dissolving 1.7 g of diethylamine in 6.7 g of methanol was added dropwise and mixed while the calcined silica particles were being stirred. Next, 166.7 g (theoretical addition amount) of γ-glycidoxypropyltrimethoxysilane (KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd., minimum coating area 330 m ² / g), which is a silane coupling agent, was added to 208.3 g of methanol. And the solution dissolved in 41.7 g of ion-exchanged water was added dropwise and mixed. Then, the mixture of the calcined silica particles, the amine, and the silane coupling agent was heated to 100 ° C. at a heating rate of 20 ° C./hour, and held at the stage of 100 ° C. for 5 hours for a heating step. Then, by cooling, the organically coated silica No. I got 1. Table 1 shows the results of average particle size, maximum particle size, maximum particle size / average particle size, coarse particle amount, nitrogen content, and resin viscosity.

Example 2
By performing the same procedure as in Example 1 except that the amine mixed by dropping is changed from diethylamine to n-hexylamine, the organically coated silica No. I got 2. Table 1 shows the results of average particle size, maximum particle size, maximum particle size / average particle size, coarse particle amount, nitrogen content, and resin viscosity.

Example 3
By performing the same procedure as in Example 3 except that the amine mixed by dropping was changed from diethylamine to aniline, the organically coated silica No. I got 3. Table 1 shows the results of average particle size, maximum particle size, maximum particle size / average particle size, coarse particle amount, nitrogen content, and resin viscosity.

Comparative Example 1
5 kg of calcined silica particles KE-S30 manufactured by Nippon Shokubai Co., Ltd. were charged into a Henschel mixer (FM20J type manufactured by Mitsui Mining Co., Ltd.) having a capacity of 20 L equipped with a heating jacket.
The Henschel mixer has a container for the mixture to be mixed and a rotating shaft with a stirring blade at the bottom of the container, and a plate-shaped blade installed along the wall surface as a device for scraping off wall deposits. A rotating shaft with a mark is installed on the upper surface of the container. While stirring the calcined silica particles, 166.7 g of γ-glycidoxypropyltrimethoxysilane (KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd., minimum coverage area 330 m ² / g), which is a silane coupling agent, is mixed with methanol. The solution dissolved in 208.3 g and 41.7 g of ion-exchanged water was added dropwise and mixed. Then, the mixture of the calcined silica particles and the silane coupling agent was heated at a heating rate of 20 ° C./hour to 120 ° C., and kept in the temperature range of 120 ° C. for 5 hours to perform a heating step. Then, by cooling, the organically coated silica No. I got 4. Table 1 shows the results of average particle size, maximum particle size, maximum particle size / average particle size, coarse particle amount, nitrogen content, and resin viscosity.

Comparative Example 2
By performing the same as in Comparative Example 1 except that the temperature range in the heating step was changed to 100 ° C., the organically coated silica No. I got 5. Table 1 shows the results of average particle size, maximum particle size, maximum particle size / average particle size, coarse particle amount, nitrogen content, and resin viscosity.

Comparative Example 3
5 kg of calcined silica particles KE-S30 manufactured by Nippon Shokubai Co., Ltd. were charged into a Henschel mixer (FM20J type manufactured by Mitsui Mining Co., Ltd.) having a capacity of 20 L equipped with a heating jacket.
The Henschel mixer has a container for the mixture to be mixed and a rotating shaft with a stirring blade at the bottom of the container, and a plate-shaped blade installed along the wall surface as a device for scraping off wall deposits. A rotating shaft with a mark is installed on the upper surface of the container. While stirring the calcined silica particles, 45 g of γ-glycidoxypropyltrimethoxysilane (KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd., minimum coverage area 330 m ² / g), which is a silane coupling agent, is added to 90 g of methanol. The dissolved solution was added dropwise and mixed. In addition, 45 g of γ-glycidoxypropyltrimethoxysilane corresponds to 0.25 times the theoretical addition amount of the silane coupling agent. Then, the mixture of the calcined silica particles and the silane coupling agent was heated at a heating rate of 20 ° C./hour to 120 ° C., and kept in the temperature range of 120 ° C. for 5 hours to perform a heating step. Then, by cooling, the organically coated silica No. I got 6. Table 1 shows the results of average particle size, maximum particle size, maximum particle size / average particle size, coarse particle amount, nitrogen content, and resin viscosity.

Comparative Example 4
The organically coated silica No. obtained in Comparative Example 3 No. 6 was crushed and classified using a jet crushing classifier (IDS-2 type manufactured by Nippon Pneumatic Co., Ltd.), and the organically coated silica No. 6 was obtained. I got 7. Table 1 shows the results of average particle size, maximum particle size, maximum particle size / average particle size, coarse particle amount, nitrogen content, and resin viscosity.

Claims (13)

It is surface-treated with a nitrogen-containing compound and an epoxy group-containing silane coupling agent.
The ratio of maximum particle size / average particle size is 2.0 or less in the particle size distribution without coarse grain cutting .
Surface-treated silica particles characterized by a nitrogen content of more than 0 ppm and 500 ppm or less on a mass basis, as measured by the Inert Gas Melting-Thermal Conductivity Method. The surface-treated silica particles according to claim 1, wherein the maximum particle size is less than 3.0 μm. The surface-treated silica particles according to claim 1 or 2, wherein the nitrogen-containing compound is an aliphatic amine, an aromatic amine, or a heterocyclic amine. The surface-treated silica particles according to any one of claims 1 to 3, wherein the coarse matter amount of 20 μm or more is 0.5% or less. The surface-treated silica particles according to any one of claims 1 to 4 , wherein the surface of the calcined silica particles is treated. The surface-treated silica particles according to any one of claims 1 to 5 , which are used for encapsulating semiconductors. A resin composition containing the surface-treated silica particles according to any one of claims 1 to 6 and a resin. A semiconductor encapsulant comprising the resin composition according to claim 7 . A surface treatment step of heating silica particles obtained by hydrolyzing and firing a condensate of alkoxysilane at a temperature of less than 150 ° C. in the presence of a nitrogen-containing compound and an epoxy group-containing silane coupling agent is included.
A method for producing surface-treated silica particles, wherein the nitrogen-containing compound is an aliphatic amine, an aromatic amine, or a heterocyclic amine . The manufacturing method according to claim 9 , wherein the temperature of the surface treatment step is 60 ° C. or higher. The production method according to claim 9 or 10 , wherein the amount of the nitrogen-containing compound used is 0.001 to 5 parts by mass with respect to 100 parts by mass of the silica particles. The production method according to any one of claims 9 to 11 , wherein the maximum particle size of the surface-treated silica particles is less than 3.0 μm. The production method according to any one of claims 9 to 12 , wherein the surface-treated silica particles are unclassified.